<SCRIPT>
function updateSched() {

  var Salon =document.getElementById("CiuroomSalon").value;
  var Sede =document.getElementById("CiuroomSede").value;

  document.getElementById("CiuroomName").value = Sede+" - "+Salon;
}
</SCRIPT>

<?php echo $this->Form->input("Sede",array('type'=>'text','onChange'=>'javascript:updateSched()','required'=>'') ); ?>
<?php echo $this->Form->input("Salon",array('type'=>'text','onChange'=>'javascript:updateSched()','required'=>'') ); ?>